Blocking A 42 Accumulation Delays the Onset and Progression of Tau Pathology via the C Terminus of Heat Shock Protein70-Interacting Protein: A Mechanistic Link between A  and Tau Pathology

The myometrium goes through physiological, cellular and molecular alterations during gestation that necessitate effective cellular proteostasis. Inducible heat shock protein A1A (HSPA1A) is a member of the 70-kDa heat shock protein A (HSPA) family, which acts as a chaperone to regulate proteostasis; however, HSPA1A also participates as a cytokine in inflammatory regulation, leading to its designation as a chaperokine. This study examined the spatiotemporal expression of HSPA1A protein in the rat myometrium throughout gestation and assessed whether it is secreted as cargo of myometrial cell-derived extracellular vesicles (EVs). Immunoblot analysis demonstrated that HSPA1A expression was markedly elevated during late pregnancy and labour and increased by uterine distension. Myometrial HSPA1A expression insitu increased in myocytes of longitudinal and circular muscle layers from Day 19 through to postpartum, specifically in the cytoplasm and nuclei of myocytes from both muscle layers, but frequently detectable just outside myocyte membranes. Scanning electron microscopy examination of samples isolated from hTERT-HM cell-conditioned culture medium, using EV isolation spin columns, confirmed the presence of EVs. EV lysates contained HSPA8, HSPA1A and the EV markers apoptosis-linked gene 2-interacting protein X (Alix), the tetraspanin cluster of differentiation 63 (CD63), tumour susceptibility gene 101 (TSG101) and HSP90, but not the endoplasmic reticulum protein calnexin. These results indicate that HSPA1A may act as a chaperokine in the myometrium during pregnancy.

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C-terminus of heat shock protein 70– interacting protein facilitates degradation of apoptosis signal-regulating kinase 1 and inhibits apoptosis signal-regulating kinase 1– dependent apoptosis

Cell Stress and Chaperones ◽

10.1379/csc-90r.1 ◽

2005 ◽

Vol 10 (2) ◽

pp. 147 ◽

Cited By ~ 61

Author(s):

Jae Ryoung Hwang ◽

Chunlian Zhang ◽

Cam Patterson

Keyword(s):

Heat Shock ◽

Heat Shock Protein ◽

Heat Shock Protein 70 ◽

Interacting Protein ◽

C Terminus

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Hsp90 rescues PTK6 from proteasomal degradation in breast cancer cells

Biochemical Journal ◽

10.1042/bj20120803 ◽

2012 ◽

Vol 447 (2) ◽

pp. 313-320 ◽

Cited By ~ 19

Author(s):

Shin-Ae Kang ◽

Hyun-Soo Cho ◽

Jong Bok Yoon ◽

In Kwon Chung ◽

Seung-Taek Lee

Keyword(s):

Breast Cancer ◽

Heat Shock ◽

Breast Carcinoma ◽

Tyrosine Kinase ◽

Protein Tyrosine Kinase ◽

Catalytic Domain ◽

Protein A ◽

Carcinoma Cells ◽

Interacting Protein ◽

Breast Carcinoma Cells

PTK6 [protein tyrosine kinase 6; also known as Brk (breast tumour kinase)] is a non-receptor tyrosine kinase, closely related to Src, but evolutionarily distinct, that is up-regulated in various cancers, including breast cancer. Hsp90 (heat-shock protein 90) was identified as a PTK6-interacting protein in HEK (human embryonic kidney)-293 cells overexpressing PTK6. Hsp90 interacted with the PTK6 tyrosine kinase catalytic domain, but catalytic activity was not required for the interaction. Geldanamycin, an Hsp90 inhibitor, significantly decreased the PTK6 protein level through proteasome-dependent degradation, but did not affect the level of Src. Geldanamycin treatment also decreased phosphorylation of PTK6 substrates due to reduced amounts of PTK6. Moreover, overexpression of CHIP [C-terminus of Hsc70 (heat-shock cognate 70)-interacting protein], a chaperone-dependent E3 ligase, enhanced proteosomal degradation of PTK6. Geldanamycin increased the interaction of PTK6 with CHIP, but decreased the interaction of PTK6 with Hsp90. We also found that endogenous PTK6 associated with Hsp90 and geldanamycin decreased expression of endogenous PTK6 in breast carcinoma cells. Finally, we report that silencing endogenous CHIP expression in breast carcinoma cells inhibited geldanamycin-induced PTK6 reduction. These results demonstrate that Hsp90 plays an essential role in regulating PTK6 stability and suggest that Hsp90 inhibitors may be useful as therapeutic drugs for PTK6-positive cancers, including breast cancer.

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Dodecin as carrier protein for immunizations and bioengineering applications

10.1101/2020.03.19.990861 ◽

2020 ◽

Cited By ~ 1

Author(s):

Florian Bourdeaux ◽

Yannick Kopp ◽

Julia Lautenschläger ◽

Ines Gößner ◽

Hüseyin Besir ◽

...

Keyword(s):

Heat Shock ◽

Fluorescent Protein ◽

Spherical Shape ◽

Interacting Protein ◽

C Terminus ◽

Heat Shock Cognate 70 ◽

A Cell ◽

Green Fluorescent ◽

Shock Proteins

AbstractIn bioengineering, scaffold proteins have been increasingly used to recruit molecules to parts of a cell, or to enhance the efficacy of biosynthetic or signaling pathways. For example, scaffolds can be used to make weak or non-immunogenic small molecules immunogenic by attaching them to the scaffold, in this role called carrier. Here, we present the dodecin from Mycobacterium tuberculosis (mtDod) as a new scaffold protein. MtDod is a homododecameric complex of spherical shape, high stability and robust assembly, which allows the attachment of cargo at its surface. We show that mtDod, either directly loaded with cargo or equipped with domains for non-covalent and covalent loading of cargo, can be produced recombinantly in high quantity and quality in Escherichia coli. Fusions of mtDod with proteins of up to four times the size of mtDod, e.g. with monomeric superfolder green fluorescent protein creating a 437 kDa large dodecamer, were successfully purified, showing mtDod’s ability to function as recruitment hub. Further, mtDod equipped with SYNZIP and SpyCatcher domains for post-translational recruitment of cargo was prepared of which the mtDod/SpyCatcher system proved to be particularly useful. In a case study, we finally show that mtDod peptide fusions allow producing antibodies against human heat shock proteins and the C-terminus of heat shock cognate 70 interacting protein (CHIP).For Table of Contents Only

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Different combinations of the heat-shock cognate protein 70 (hsc70) C-terminal functional groups are utilized to interact with distinct tetratricopeptide repeat-containing proteins

Biochemical Journal ◽

10.1042/bj3590419 ◽

2001 ◽

Vol 359 (2) ◽

pp. 419-426 ◽

Cited By ~ 26

Author(s):

Shin-Jen WU ◽

Fu-Hwa LIU ◽

Su-Ming HU ◽

Chung WANG

Keyword(s):

Heat Shock ◽

Functional Groups ◽

Luciferase Activity ◽

Inhibitory Effect ◽

Tetratricopeptide Repeat ◽

Interacting Protein ◽

C Terminus ◽

Heat Shock Cognate Protein ◽

Cognate Protein

A group of tetratricopeptide repeat (TPR)-containing proteins has been shown to interact with the C-terminal domain of the 70kDa heat-shock cognate protein (hsc70). In the present study, the effect of the TPR-containing proteins, including the C-terminus of hsc70-interacting protein (CHIP), TPR1 and human glutamine-rich TPR-containing protein (hSGT), on refolding of luciferase by DnaJ and hsc70 was investigated. These proteins inhibited the restoration of luciferase activity by the chaperones. The inhibitory effect exerted by TPR1 and hSGT depended upon their binding to hsc70. However, the interaction with hsc70 did not appear to be required for the inhibition of luciferase refolding by CHIP. We also demonstrate that the peptide, GPTIEEVD, corresponding to the C-terminal end of hsc70, abolished the association of [3H]hsc70 with CHIP, TPR1 and hSGT. This implied that the GPTIEEVD motif of hsc70 was responsible for interacting with these TPR-containing proteins. However, the GGXP-repeats (where X is any aliphatic residue), another C-terminal conserved motif of vertebrate hsc70s, were not essential for interacting with the TPR-containing proteins. On the basis of mutagenesis studies, it was clear that a unique combination of the functional groups in the GPTIEEVD motif were utilized to interact with each TPR-containing protein, suggesting that inhibitors can be designed and used to elucidate the functional role of these interactions.

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